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We've had numerous bug reports about how (1) IF NOT EXISTS clauses in ALTER TABLE don't behave as-expected, and (2) combining certain actions into one ALTER TABLE doesn't work, though executing the same actions as separate statements does. This patch cleans up all of the cases so far reported from the field, though there are still some oddities associated with identity columns. The core problem behind all of these bugs is that we do parse analysis of ALTER TABLE subcommands too soon, before starting execution of the statement. The root of the bugs in group (1) is that parse analysis schedules derived commands (such as a CREATE SEQUENCE for a serial column) before it's known whether the IF NOT EXISTS clause should cause a subcommand to be skipped. The root of the bugs in group (2) is that earlier subcommands may change the catalog state that later subcommands need to be parsed against. Hence, postpone parse analysis of ALTER TABLE's subcommands, and do that one subcommand at a time, during "phase 2" of ALTER TABLE which is the phase that does catalog rewrites. Thus the catalog effects of earlier subcommands are already visible when we analyze later ones. (The sole exception is that we do parse analysis for ALTER COLUMN TYPE subcommands during phase 1, so that their USING expressions can be parsed against the table's original state, which is what we need. Arguably, these bugs stem from falsely concluding that because ALTER COLUMN TYPE must do early parse analysis, every other command subtype can too.) This means that ALTER TABLE itself must deal with execution of any non-ALTER-TABLE derived statements that are generated by parse analysis. Add a suitable entry point to utility.c to accept those recursive calls, and create a struct to pass through the information needed by the recursive call, rather than making the argument lists of AlterTable() and friends even longer. Getting this to work correctly required a little bit of fiddling with the subcommand pass structure, in particular breaking up AT_PASS_ADD_CONSTR into multiple passes. But otherwise it's mostly a pretty straightforward application of the above ideas. Fixing the residual issues for identity columns requires refactoring of where the dependency link from an identity column to its sequence gets set up. So that seems like suitable material for a separate patch, especially since this one is pretty big already. Discussion: https://postgr.es/m/10365.1558909428@sss.pgh.pa.us |
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| brin | ||
| commit_ts | ||
| dummy_index_am | ||
| dummy_seclabel | ||
| snapshot_too_old | ||
| test_bloomfilter | ||
| test_ddl_deparse | ||
| test_extensions | ||
| test_ginpostinglist | ||
| test_integerset | ||
| test_misc | ||
| test_parser | ||
| test_pg_dump | ||
| test_predtest | ||
| test_rbtree | ||
| test_rls_hooks | ||
| test_shm_mq | ||
| unsafe_tests | ||
| worker_spi | ||
| Makefile | ||
| README | ||
Test extensions and libraries ============================= src/test/modules contains PostgreSQL extensions that are primarily or entirely intended for testing PostgreSQL and/or to serve as example code. The extensions here aren't intended to be installed in a production server and aren't suitable for "real work". Furthermore, while you can do "make install" and "make installcheck" in this directory or its children, it is NOT ADVISABLE to do so with a server containing valuable data. Some of these tests may have undesirable side-effects on roles or other global objects within the tested server. "make installcheck-world" at the top level does not recurse into this directory. Most extensions have their own pg_regress tests or isolationtester specs. Some are also used by tests elsewhere in the tree. If you're adding new hooks or other functionality exposed as C-level API this is where to add the tests for it.